This invention relates to a communication device and method for arbitrating between the communication operations of collocated transceivers capable of causing mutual interference.
Many modern communication devices such as smartphones allow communications by means of multiple radio protocols operating over common or adjacent frequency bands. For example, smartphones typically include Bluetooth and WiFi transceivers that both operate in the 2.4-2.5 GHz ISM frequency band. This can lead to interference problems between the radio protocols and a degradation in performance.
In order to mitigate the mutual interference experienced by wireless transceivers operating in close spectral and physical proximity, arbitration schemes are normally necessary to control the timing and/or frequency of transmissions by the collocated transceivers. Conventional arbitration schemes typically involve scheduling the transmissions of a first transceiver around the communications of a second collocated transceiver, such that the first transceiver does not transmit when the second transceiver is (or could be) communicating. Typically, communications of the second transceiver would be of higher priority or of a communication protocol that operates according to fixed known time slots (e.g. Bluetooth).
Some arbitration schemes, such as the packet traffic arbitration schemes described in IEEE 802.15.2-2003, involve per-packet or per-communication burst arbitration between transceivers at the data link layer. Typically, such arbitration involves identification of temporally or spectrally-overlapping communication activities and deferral or cancellation of those communication activities that are identified as being of lower priority. The priority could be an indicated priority level of the communication activities or a priority level determined at the arbitrator according to some predetermined algorithm. However, whilst such link layer arbitration schemes are effective at avoiding interference at the physical layer, they do not address the significant problem of poor link or transport layer reaction to the variable nature of services provided beneath them.
There is therefore a need for an improved arbitration scheme that addresses these problems.